This is created when you visit the website and agree to accept cookies.
This states whether the users browser is accepting cookies are not.
Like lots of other sites, I use Google Analytics. This collects anonymous data of how people are using this site and then provide me with visitor statistics, details of page views etc., which is very helpful for us in trying to improve the website.
There is a browser add-on which allows you to you can opt-out of being tracked by Google Analytics at http://tools.google.com/dlpage/gaoptout
Most web browsers allow some control of most cookies through the browser settings. To find out more about cookies, including how to see what cookies have been set and how to manage and delete them, visit http://www.allaboutcookies.org.